The present invention relates to a brake force generator for a motor vehicle brake system, comprising a displaceable force input element connected or connectable to a brake pedal, a control valve actuable in accordance with a displacement of the force input element, a chamber arrangement disposed in a booster housing and controllable by means of the control valve and comprising at least one vacuum chamber and at least one working chamber, which are separated from one another by at least one movable wall connected to the control valve, and a force output element for supplying a brake force to a downstream brake system, wherein the control valve with the force output element is biased by a resetting spring into a normal position, wherein the resetting spring is supported by its one end against the control valve.
Such a brake force generator is prior art. Thus, the document EP 1 422 116 B1 discloses a brake force generator of this type. In this brake force generator a resetting spring arrangement comprising two resetting springs is provided, which is supported by its one end against a control valve housing of the control valve. By its other end the resetting spring is supported against a master cylinder arrangement. As a result, on the one hand the master cylinder arrangement is biased into a normal position and on the other hand the control valve housing and the movable wall coupled thereto are biased into their normal position. Experience has shown however that during the assembly of such brake force generators, in particular prior to mounting of the brake force generator on the downstream master cylinder arrangement, one of the resetting springs or the entire resetting spring arrangement may fall out of the brake force generator or may become skewed. As a consequence of this, the resetting springs have to be retro-fitted, this on the one hand increasing the assembly outlay and on the other hand being susceptible to faults, for example because the springs are fitted the wrong way round or suffer damage when they fall out.